Editing Anethole (section)

== Structure and production ==
Anethole is an aromatic, [[Saturated and unsaturated compounds|unsaturated]] [[ether]] related to [[Monolignol|lignols]]. It exists as both [[Cis-trans isomerism|''cis''–''trans'' isomers]] (see also [[E-Z notation|''E''–''Z'' notation]]), involving the double bond outside the ring. The more abundant isomer, and the one preferred for use, is the ''trans'' or ''E'' isomer.<ref name="chemistry-europe.onlinelibrary.wiley.com">{{cite journal|last1=Zhang|first1=Hongwei|last2=Lim|first2=Candy Li-Fen|last3=Zaki|first3=Muhammad|last4=Jaenicke|first4=Stephan|last5=Chuah|first5=Gaik Khuan|date=2018|title=A Dual-Functional Catalyst for Cascade Meerwein–Pondorf–Verley Reduction and Dehydration of 4′-Methoxypropiophenone to Anethole|url=https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cssc.201801340|journal=ChemSusChem|language=en|volume=11|issue=17|pages=3007–3017|doi=10.1002/cssc.201801340|pmid=29927044|bibcode=2018ChSCh..11.3007Z |s2cid=49342669|issn=1864-564X|url-access=subscription}}</ref>

Like related compounds, anethole is poorly soluble in water. Historically, this property was used to detect adulteration in samples.<ref>{{cite journal|title=Essential oils|year=1920|volume=14|issue=17|pages=3753–3755|first=S.|last=Waldbott|journal=Chemical Abstracts|url=https://books.google.com/books?id=isq2AAAAIAAJ&pg=PA3753}}</ref>

Most anethole is obtained from [[turpentine]]-like extracts from trees.<ref name=Ullmann /><ref>{{cite patent|country=US|number=4902850|title=Purification of anethole by crystallization|inventor=Davis, Curry B.|gdate=1990-02-20}}</ref> Of only minor commercial significance, anethole can also be isolated from essential oils.<ref>{{cite book|title=Chopra's Indigenous Drugs of India|first1=R. N.|last1=Chopra|first2=I. C.|last2=Chopra|first3=K. L.|last3=Handa|first4=L. D.|last4=Kapur|publisher=Academic Publishers|year=1958|edition=2nd|pages=178–179|url=https://books.google.com/books?id=2HyC4-GJ50YC&pg=PA178|isbn=978-81-85086-80-4}}</ref><ref name="Ashurst">{{cite book|title=Food Flavorings|first=Philip R.|last=Ashurst|publisher=Springer|year=1999|page=460|url=https://books.google.com/books?id=hrWuqmtwJiEC&q=anethole|isbn=978-0-8342-1621-1}}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{cite journal|title=Liquid CO<sub>2</sub> Extraction and NMR Characterization of Anethole from Fennel Seed: A General Chemistry Laboratory|first1=B. R.|last1=Bodsgard|first2=N. R.|last2=Lien|first3=Q. T.|last3=Waulters|journal=Journal of Chemical Education|date=2016|volume=93|issue=2|pages=397–400|doi=10.1021/acs.jchemed.5b00689|bibcode=2016JChEd..93..397B}}</ref><!-- pages 11, 33, 34-->

{| class="wikitable"
|-
! Essential oil
! World production
! ''Trans''-anethole
|-
| Anise
| 8 tonnes (1999)
| 95%
|-
| Star anise
| 400 tonnes (1999), mostly from China
| 87%
|-
| Fennel
| 25 tonnes (1999), mostly from Spain
| 70%
|}

Currently Banwari Chemicals Pvt Ltd situated in Bhiwadi, Rajasthan, India is the leading manufacturer of anethole. It is prepared commercially from 4-methoxy[[propiophenone]],<ref name="chemistry-europe.onlinelibrary.wiley.com"/><ref>{{cite journal|date=2021-08-01|title=Hydrophobicity and co-solvent effects on Meerwein-Ponndorf-Verley reduction/dehydration cascade reactions over Zr-zeolite catalysts|url=https://www.sciencedirect.com/science/article/abs/pii/S0021951721001962|journal=Journal of Catalysis|language=en|volume=400|pages=50–61|doi=10.1016/j.jcat.2021.05.011|issn=0021-9517|last1=Zhang|first1=Hongwei|last2=Quek|first2=Zhan Jiang|last3=Jaenicke|first3=Stephan|last4=Chuah|first4=Gaik-Khuan|s2cid=236342527|url-access=subscription}}</ref> which is prepared from [[anisole]].<ref name=Ullmann />